Manufacture of plates for printing.



No. 774,528. PATENTED NOV. 8, 1904. E. A. NEBEN.

MANUFACTURE OF PLATES FOR PRINTING.

I APPLICATION FILED APR. 6, 1904. NO MODEL.

WITNESSES: INVENTOR 5 lzweaifi ./7/6 67Z y K BY ATTORNEYS? UNITED STATESPatented November 8, 1904.

ERNEST A. NEBEN, OF NEW YORK, N. Y

MANUFACTURE OF PLATES FOR PRINTING.

SPECIFICATION forming part of Letters Patent No. 774,528, dated November8, 1904:.

Application filed April 6, 1904- T0 (I/ZZ whmn it may concern: I

Be it known that I, ERNEST A. NEBEN, a citizen of the United States, anda resident of the city of New York, borough of Brooklyn, in the countyof Kings and State of New York, have invented new and usefulImprovements in the Manufacture of Plates for Printing, of which thefollowing is a full, clear, and exact description.

The invention relates to the art of preparing relief-plates for printing'typographically therefrom.

The object of the invention is to provide certain new and usefulimprovements in the manufacture of plates, whereby zinc or copper platesare produced for receiving any desired design in half-tone effects,together with the necessary contrast of high lights, solids, and shadesto allow of using the plates for the reproduction of color work for finecolorprinting.

The plate consists of a metallic body having a polished face and agrain, dots, stipples, or the like on the said face and formed by anacid-resisting substance hardened by being burned on the said face, thesaid grain, stipples, dots, &c., permitting the artist to apply thedesign by the use of transfer-paper and to stop out desired portions byan acid-resisting substance, which allows an etching of the plate, anumber of such plates being treated corresponding to the number of thecolors in the original design.

In detail I proceed as follows, special reference being had to theaccompanying drawings, forming a part of this specification, in whichsimilar characters of reference indicate corresponding parts in all theviews.

Figure 1 is a side elevation of a zinc or copper plate having a polishedface. Fig. 2 is a similar view of the same, showing the polished facecoated with the sensitized substance. Fig. 3 is a like view of theplate, having the coating and a screen superimposed on the coating. Fig.A is a side elevation of the plate provided with a field. Fig. 5 is aside elevation of the heater for heating the plate to indurate or hardenthe field on the plate. Figs. 6, 7 and 8 are sectional side elevationsillustrating the successive steps for producing the Serial No. 201,841.(No model.)

printing-plate, and Fig. 9 is a sectional side elevation of the finishedprinting-plate.

The polished face of a Zinc, copper, or similar metallic plate A isprovided with a thin coating B of a sensitized substance such as is usedon ordinary photographic plates or films. Anegative C, representingdots, lines, stipples, cross-cut lines, grain, &c., is superimposed onthe coating B, and both the negative and the plate A, with its coating,are then subjected to an exposure of light, after which the negative isremoved and the plate is washed to remove the soluble portions of thecoating and to leave an insoluble field B in the form of dots, lines,stipples, cross-cut lines, grain, &c., according" tothe nature of thenegative C used. The plate A is now preferably subjected to heat toindurate and harden the field B, represented by the dots, stipples, &c.The heating is-preferably done on a heater, such as shown in Fig. 5, andwhich consists of a grate D for the plate A to rest on and gas-burners Dbelow the said grate. The plate prepared as described is now ready forthe market; but it is understood that if the plate in'its presentcondition were used in printing it would produce a solid impression.

In order to use the prepared plate for making a printing-plate forcolor-work, for instance, the user proceeds as follows: For theproduction of a four-color design, for instance, it is necessary to makethree impressions on lithographic transfer-paper from a key-plate, andthe impressions are then transferred on three plates prepared as abovedescribed. The artist with the aid of a brush or the like now treats'each plate separately, according to the color to be reproduced, andapplies an acid-resisting substance Esuch as asphaltum varnish-{see Fig.6) on the portions representing the solids pertaining to the respectivecolor of the original design, and then the plate is subjected to anetching agent in the usual manner, whereby the acid attacks only thoseportions in the polished face of the plate A that are not covered by thesaid dots, stippies, &c., forming the face B and the acidresistingsubstance E. ,(See Fig. 6.) By this treatment the face B of the plate Ais left with the solids B and very flat dot portions B printing heavydots to the strength of the color desired when the plate is used inprinting. In order to produce half-tone tints or somewhat lighter dotsB, as called for by the original design, it is again necessary for theartist to apply an acid-resisting substance E (asphaltum varnish) ontothe portions of the fiat printing-face desired to remain in the plate toprotect the said portions from the second acid-bath to which the plateis now subjected. The acid now eats away on all the sides of the dots,stipples, &c., of the plateface not covered by the acid-resistingsubstances E E, thereby rendering the plate-face portions located underthe uncovered dots, stipples, &c., smaller and rounder, and forming thecross-lines in the plate-face deeper and wider until the desiredhalf-tone tint B is reached. As the original subject-matter also callsfor some very light tints B, it is necessary for the artist to stop outcorresponding portions of the half-tone tint B by the use of anacid-resisting substance E (asphaltum varnish,) and then the plate isagain subjected to an acid-bath to again reduce the face portion underthe remaining non-covered dots, stipples, &c., to form exceedingly finesharp dots, stipples, &c., in the face of the plate A. The parts of theface not desired to print at all are now routed out or otherwiseremoved, as indicated at B in Fig. 9. As the field B is exceedinglythin, it is evident that as the acid of the different baths eats awayportions of the plate-face under the dots, stipples, &c., of the field Btheir overhanging edges crumble or break, and only the portions on thepolished non -acid attached portions of the face of the plateAremain andform an enamel or indurated hardened printing-face on the plate A. Eachof the plates is treated, as above described, according to the color tobe printed by this particular plate-that is, the solids B for this colorare first stopped out. Then the plate is subjected to an acid-bath toproduce portions B printing to the strength of the color. Then a portionof the portion B is stopped out and the plate subjected to an acid-bathto form half-tone tints B, a portion of which in turn is stopped out andthe plate again subjected to an acid-bath for producing high lighttints, such as at B and the portion B not to print at all is finallyrouted out or otherwise bodily removed by suitable tools in the hands ofthe artist. It is understood that the successive stopping-out andsubsequent etching processes of the plate may be carried on any desirednumber of times to produce all the gradations in tone called for by theoriginal subject-matter to be reproduced. The portions E E and E of theacidresisting substances are now removed by washing the plates orotherwise treating the same, and then the plates are ready for use inthe printing-press to reproduce the subject in four colors.

It is understood that the field B on the face of the plate A, andconsisting of dots, stipples, grain, or the like is sufficientlyindurated or hardened to resist fracture or marring while the plate isin transportation or is treated by the artist, as above described. Byindurating or hardening the field the latters holding property on theface of the plate A is increased to such an extent that the fieldadheres persistenly to the plate-face to allow carrying out theprocesses of stopping out, etching, and printing without danger ofdisplacement of the dots, stipples, 620'. Although I have found itexpedient to indurate or harden the plate by the application of heat, Ido not limit myself to this process, as other means may be employed toproduce the same resultthat is, to provide the polished face of theplate with an enamel printing-field of dots, stipples, &c.

It is understood that, if desired, the enamel printing-field B, shown inthe finished printing-plate, Fig. 9, may be removed by Washing the platewith a suitable solution or otherwise treating the plate for thepurpose, andv in case such field is removed the plate will print thesame as with the field B left thereon on account of the solids,half-tones, and gradations thereof now being integral parts of thepolished face of the printing-plate. In practice, however, I have foundthat it is not necessary to remove the printing-field B.

Having thus described my invention, I claim as new and desire to secureby Letters Patent The herein-described process for producingrelief-printing plates, consisting in photographically producing a fieldof insoluble matter on the face of a plate, indurating the said field,to harden the same and cause it to adhere to the plate-face, thentransferring the subject-matter of the design onto the said field, thenalternately stopping out portions of the field and plate and etching thesame, and finally removing the stopping-out substance from the face ofthe metal plate.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

ERNEST A. NEBEN.

Witnesses:

THEo. Gr. HOSTER, EVERARD B. MARSHALL.

